Fiber-type light conversion device

Abstract

A fibre-type light conversion device comprises a fibre-type conversion element for changing the wavelength of an incident light and a converging lens for converging said incident light whose wavelength is changed by the conversion element. The device is characterized in that the converging lens is a single lens having an aspherical surface configured such that a distance Zi from a plane perpendicular to an optical axis of the lens and passing an extremity of the lens to a point on the aspherical surface having a height Y from the optical axis is expressed by the following equation ##EQU1## where Ci is an inverse number of the radius of curvature of the "i"th surface at an intersecting point between the "i"th surface and the optical axis, Ki, A 1 (i)˜A 10 (i) are constants, and Y is the height from the optical axis to the refracting surface.

What is claimed is: 
     
       1. A fibre-type light conversion device comprising a fibre-type conversion element for changing the wavelength of an incident light, and a converging lens for converging said incident light whose wavelength is changed by said conversion element, wherein said converging lens is a single lens having an aspherical surface configured such that a distance Zi from a plane perpendicular to an optical axis of said lens and passing an extremity of said lens to a point on said aspherical surface having a height Y from the optical axis is expressed by the following equation ##EQU3## where Ci is an inverse number of the radius of curvature of an "i"th surface at an intersecting point between the "i"th surface and the optical axis, Ki, A 1  (i)˜A 10  .sup.(i) are constants, and Y is the height from the optical axis to the refracting surface of said lens.